Vapor lock 70 Cuda 383 Shaker

[moper]

I admire your integrity in regard to "someone elses work".
The operating temp of the engine is 190+ and todays fuels will run quite well at 205-210. I thin kthe issue is yes - the fuel evaporates quicker. But it's not making good enough use of the fuel that is left in the carb. My truck has a 195 operating temp and routinely hits 210+, including idling for long periods before being shut down. It's a 360 with an aluminum intake and the crossover open as it's also my plow. The only time it turns over more than twice is if it's been sitting a week - in which case I have to turn it over for about 20 seconds before I "pump twice and turn the key". I would suggest a quick test for you.
Let the car warm up to operating temp, in fact, let it idle until it's hot (200°). Then shut it down. Using a felt tip pen, mark the base of the distributor and the block in one straight line. Then, loosen the distributor hold down and rotate the distributor clockwise so the two ends of the pen mark are spaced about 1/8" apart and retighten the hold down. Then let it sit for as long as it normally would when you notice a problem. Then get in and turn the key without hitting the gas. If it starts better - you need to set the ignition curve up and then retune the carb a little. If it doesn't change, loosen the distributor and move it back so the marks line up and you're back where you were.
My truck doesn't even turn once when it's really hot - and this engine is slated for replacement in a couple months as it's whipped. I think the fuel is blamed for a lot of base tuning issues in this regard.

 

[Racer57]

I'll definitely keep your hint in mind, and try it out.

In case I haven't made it clear.... when I start the engine whether its cold or warmed up good it will fire just as quick as any vehicle should. However when it gets hot (200+ while sitting), it turns over just as fast as before, but it won't start like it should.

 

[moparleo]

After you try those ,try this. You say that it cranks just as fast hot as it does cold. The only difference is that it won't start right back up. So lets check fuel level. Warm the engine up to where you think is hot enough for the problem to happen. Remove the air cleaner and while looking down the primary side of the carb, work the throttle to see if any fuel is squirting out of the fuel nozzles when working the accelerator pump. If not, depending on the carb that you are using, if it is a Holley the pump diaphragm is leaking or the fuel level is too low. If it is a Carter AFB/AVS type, the pump piston might not be making a tight seal when pumping or the pump passage may be restricted. The Thermo-Quad has an internal tube going from the pump to the nozzles and may be loose/broken. Obviously make sure that the key is off when you do this.

 

[Racer57]

Its a 600 Eldebrock.

I'll check it out as soon as "real life" allows me. Thanks again.